The Huawei Mate X2 is a cutting-edge foldable smartphone with an innovative design that pushes mobile technology to new heights. Due to a charging incident, the phone smoked, leaked current, and had a black screen, rendering it unusable. In this article, you will learn how to fix a damaged motherboard on a HUAWEI Mate X2 due to improper charging. This guide provides valuable insight into the repair process, regardless of whether you are a technician or a DIY enthusiast.
Phone Details:
Model: HUAWEI Mate X2
Announced: 2021, February 22
Defect Phenomenon:
- The phone emitted smoke during charging and subsequently failed to charge.
- The screen turned black, and the phone could no longer be powered on.
- A diagnosis at a repair shop indicated motherboard damage, with a 10mA current leakage on the battery (BATT), preventing the phone from booting.
Troubleshooting
1: Initial Check:
- The phone was disassembled, revealing a motherboard that appeared new and had not been previously repaired.
- Connecting the motherboard to a DC power supply revealed a 10mA current leakage.
2: Boot Attempt:
- The phone was assembled and an attempt to boot was made.
- The HUAWEI logo appeared briefly, then the screen went black again.
- Suspecting a battery detection issue, the battery was activated and tested again, but the phone still couldn’t boot.
2: Thermal Imaging
- The DC power supply showed current leakage, so a thermal imager was used to identify the overheated component.
- A small hole was discovered around the display connector under a microscope, indicating potential rail damage beneath the surface.
Even though it’s only a very tiny hole, it’s a serious problem, as the underlying layers with many rails are broken.
Repair Process
1: Damage Assessment:
- The connector was removed to assess the extent of the damage.
- The small hole revealed deeper damage than initially expected, with multiple PCB layers likely affected.
2: Repairing Broken Rails
- The surrounding shielding covers were removed to access the damaged area.
- The PCB layers were carefully scratched away using a blade knife to expose the broken rails.
- Around 3-4 layers of rails were found to be broken.
3: Jumping Wires
- A UV mask was applied to cover the grounding rail layer.
- Wires were jumped across the broken layers, ensuring each rail was connected to its correct destination without causing shorts or bridges.
- This delicate process took approximately an hour to complete.
4: Reassembly and Testing
- The connector and surrounding components, such as small capacitors and resistors, were soldered back onto the board.
- The phone was reassembled and connected to the DC power supply.
- The current leakage was no longer present, and the phone successfully booted up.
Tips for Prevention
- The issue may have been caused by using a poor-quality charger or charging cable.
- To avoid similar issues, it’s important to use reliable and scientifically tested charging methods to keep your phone safe.
Conclusion
The Huawei Mate x2 charge to smoke, and it cannot boot or turn on isn’t normal, but it does happen occasionally. REWA Tech wrote this article based on a case study. This tutorial is intended to help repair technicians and DIYers learn something new.
